In the evolution of aerospace vehicles, particularly space vehicles and military aircraft, there has been a continuous search for new, low weight, high strength materials. Because of the extreme operating environments experienced airframes and engines, their component materials must function reliably throughout a large range of temperatures and pressures during a long lifetime. Moreover, the needs for improved system performance usually include economic demands for greater process efficiencies and reduced manufacturing costs.
High heat flux systems, such as heat exchanger panels and leading edge components of reentry vehicles, can be critical items in the safe operation of aerospace vehicles. Some of these systems use high pressure fluid filled tubes to transfer heat as rapidly as possible away from high temperature surfaces. As the performance requirements for such systems have increased, a need has developed for improved, high strength, high heat conductivity materials that can be fabricated into tubes.
Prior attempts to fabricate graphite fiber reinforced copper tubes, for example, have resulted in distortion of the copper tube assemblies and nonuniform distribution of the graphite fibers. These difficulties were determined to be associated with compressive stresses developed during forming of the graphite fiber copper tube assemblies. As a result of the compressive forces used for fiber consolidation, a fold would develop in the tube causing the fibers to gather into a distorted region of the tube. Therefore, new methods of fabrication were investigated to construct high quality fiber reinforced metal tubes with a uniform distortion of fibers.